High Selectivity Dual-Band Bandpass Filter with Tunable Lower Passband

Figure 1

(a) The proposed stub-loaded trimode resonator; (b) odd-mode circuit of (a); (c) even-mode circuit of (a); (d) odd-mode circuit of (b); (e) even-mode circuit of (b); (f) odd-mode circuit of (c); (g) even-mode circuit of (c).